Children’s hearing A guide for parents

Children’s hearing
A guide for parents
Content
Introduction
3
Communication milestones
4
Signs of hearing difficulties
6
How we hear
8
Children‘s hearing
10
Hearing loss indicators
12
What to do if you think your child has a hearing loss
14
Types of audiological evaluations
15
Technological solutions
16
Where to get help
18
3
Introduction
Building the future
Children are our future. By giving them
access to the wealth of sounds that enrich
today’s world, we can help them to develop
the auditory skills they need to build their
future.
Phonak has been committed to providing
high-tech solutions for children with
hearing loss for over 35 years. Innovative
technology has enabled us to successfully
meet growing needs. Many of the
developments in the field of pediatrics
have led the way for the progress of Phonak
hearing systems in general. The trail of
innovation continues and it remains a
priority at Phonak to help prepare today’s
children for tomorrow, at the same time
giving practical support to their parents.
Hearing is one of a child’s most precious
senses. Through hearing, children develop
language and communication skills, marvel
at the sounds of our bustling world, learn
to read, appreciate music and be warned of
approaching danger.
Hearing loss does not put an end to all this
if amplification is provided early. Often, by
acting early and selecting the right
technological solutions, such sounds,
including speech can be learned. The
outlook for children with hearing
impairment is now bright with a full range
of options. The information in this booklet
is designed to help you understand:
Children‘s hearing
Speech and language development
n How to monitor hearing throughout
childhood
n Types of hearing loss
n How to protect your child’s hearing and
prevent hearing loss
n
n
4
Communication milestones
The cochlea which is the sensory organ of hearing,
attains full adult size and enables the child to hear
by the 20th week of pregnancy. This means that
children can be exposed to the sound of their
mothers and other voices even before they are
born.
After birth, a newborn child’s cochlear sensitivity
is similar to that of adults, but babies must learn
how to use their hearing to form the foundations
of communication.
Localization
One of the earliest and easiest auditory skills to
observe in your baby is localization, the ability to
pinpoint the source of a sound. Because we hear
through two ears (binaurally), we can localize
sounds with extreme accuracy.
Observing your child’s localization ability
In general, newborns will move or widen their eyes
when they hear a loud sound. This is known as the
startle reflex and many loud sounds should induce
this reflex. When your infant gets to about five or
six months, you can better observe a true
localization response by making soft sounds
behind or to the side of your infant while he or she
is looking straight ahead (be sure you are out of
view when making the sounds). A soft rattle shake
or a whisper should prompt your baby to turn his
or her head toward the sound.
While we expect infants to startle when presented
with very loud sounds, it is most important to see
how well your baby responds to soft sounds (such
as the speech sound “s“).
During the first year, your baby will refine listening
skills and should alert to and look for the sources
of common sounds around the home, such as a
ringing doorbell or telephone, slamming door,
children playing, a musical toy and speech.
5
Your child’s speech and language
development
Age developmental milestones:
9 months
Demonstrate an understanding of simple words
“mommy,“ “daddy,“ “no,“ “bye-bye.“
10 months
Babbling should sound “speech like,” with single
syllables strung together (“da-da-dada”). The first
recognizable words emerge at about this time.
1 year
One or more real words spoken.
18 months
Understand simple phrases, retrieve familiar
objects on command (without gestures) and point
to body parts. Also should have a spoken vocabulary
between 20 and 50 words and use short phrases
(“no more,“ “go out,“ “mommy up“).
24 months
Spoken vocabulary should be at least 150 words,
coupled with the emergence of simple two word
sentences. Most speech should be understandable
to adults who are not with the child daily. Toddlers
also should be able to sit and listen to read-aloud
picture books.
3 to 5 years
Spoken language should be used constantly to
express wants, reflect emotions, convey
information and ask questions. A pre-schooler
should understand nearly all that is said. Vocabulary
grows from 1000 to 2000 words, which are linked
in complex and meaningful sentences. All speech
sounds should be clear and understandable by the
end of the preschool period.
These milestones are rough “rules of thumb“ for
the majority of children. If your child is more than
2-3 months delayed compared to the abovementioned age-groups, it might indicate hearing
loss or delayed speech-language development.
6
Signs of hearing difficulties
You should always be aware when your child does
not respond appropriately to sounds. Sometimes a
lack of response is attributed to inattention, but it
is important to determine if inconsistent or no
responses actually stem from an inability to hear.
Common signs that children may not be hearing
normally
n Not aware someone who is out-of-view is
talking, especially when distractions are minimal
n Startled or surprised look when they realize their
name has been called (at a normal or even fairly
loud level)
n Using “what?“ or “huh?“ frequently
n Intently watching the faces of speakers
n Sitting close to the television set when the
volume is sufficient for other family members
n Increasing the volume of the TV or stereo to
unreasonably loud levels
n Not responding to voices over the telephone
and/or switching ears continually
n Not reacting to intense, loud sounds
The single most important sign of possible hearing
loss, however, is a lack or delayed development of
speech and language.
7
8
How we hear
Understanding the basic anatomy and function of
the ear will help you identify conditions that can
affect your child’s hearing.
The ear can be divided into three parts: the outer,
middle and inner ear.
The outer ear
The outer ear consists of the auricle, also called the
pinna. The pinna collects and channels sound into
the external ear canal (auditory canal). The ear
canal amplifies the sound waves and further
funnels them toward the eardrum (tympanic
membrane).
The middle ear
The eardrum vibrates in response to the movements
of sound waves entering the ear canal. There are
also three small bones (ossicles) in the middle ear.
These bones, the malleus (hammer), the incus
(anvil) and the stapes (stirrup), vibrate, magnifying
the movements of the eardrum and transmitting
the motions to the inner ear.
The inner ear
The cochlea is the actual sensory organ of hearing
and is located in the inner ear. The chambers of the
cochlea are filled with fluid. As the bones in the
middle ear move in response to sound waves, they
cause the fluid in the cochlea to also move. This
stimulates thousands of sensory hair cells which
produce small electrical charges. These electrical
signals travel along the auditory nerve to the brain
where they are processed as the “sounds” we
hear.
9
Parts of the ear
Pinna
Semicircular Canals
Malleus
Incus
Stapes
Eardrum
Eustachian Tube
Auditory Nerve
Auditory Canal
Outer Ear
Cochlea
Middle Ear
Inner Ear
10
Children’s hearing
There are conditions which may occur before birth,
during infancy or in childhood that may affect a
child‘s ability to hear normally. Essentially, there
are two types of hearing loss: conductive and
sensorineural.
Conductive hearing loss (medically treatable
conditions)
With a conductive hearing loss, the inner ear
functions normally, but something affects the
outer or middle ear, hindering sound from reaching
the inner ear. Conductive hearing losses are mildto-moderate in degree and are usually temporary
and treatable.
You can simulate a conductive hearing loss by
plugging your ears with your fingers. Sounds from
the outside are softer while your own voice
actually sounds louder than normal. The following
are some common causes of conductive hearing
loss.
Earwax (cerumen)
When wax becomes impacted in the ear canal, it
acts as an ear plug, blocking sound waves from
striking the eardrum. Excessive wax may be
softened with wax-softening drops and flushed
out or removed by a physician or other trained
personnel. Q-tips should never be used to remove
impacted wax because they may push the wax
deeper into the canal or puncture the eardrum if
inserted too deeply.
Foreign objects
Small objects put in the ears, such as beads or
food, can block sound or rupture an eardrum.
Swimmer’s ear
This painful bacterial infection can cause the ear
canal to swell shut, resulting in a temporary
hearing loss, this occurs when the ear canal
remains wet after bathing or swimming.
Otitis media (middle ear infection)
This is the most common cause of conductive
hearing loss in children. Otitis media is a general
term used to describe a variety of conditions
affecting the middle ear. More than 85% of all
children will have at least one ear infection in
childhood. In fact, ear infections are second only
to well-baby checks as the reason for visits to a
physician.
There are various forms and causes of otitis media.
The single most frequent factor is infected
adenoids which harbor bacteria or obstruct the
Eustachian tube that connects the middle ear with
the back of the nose (nasopharynx).
Ear infections also may result from upper
respiratory infections or exposure to cigarette
smoke. The two most common types of otitis
media are acute otitis media and otitis media with
effusion.
11
Acute otitis media (AOM) – ear pain, fever,
restlessness and some hearing loss are common
symptoms of acute otitis media (suppurative otitis
media). This type of ear infection may heal by itself
or respond to antibiotics.
In some cases, acute otitis media may cause the
ear drum to rupture, causing fluid drainage from
the ear. If left untreated, it could lead to more
severe middle or inner ear conditions.
Otitis media with effusion (OME) – frequently
follows an episode of acute otitis media. OME
occurs when fluid remains in the middle ear,
impeding ear drum vibrations and middle ear bone
movement. This can cause mild-to-moderate
degrees of hearing loss. In very young children,
this hearing loss may hinder spoken language
development.
The treatment of otitis media with effusion is
controversial. Sometimes the infection heals on its
own or with the help of antibiotics or myringotomy
to drain the fluid, and other times it resists these
conventional approaches. If the infection persists
and hearing loss is present, ventilation or pressure
equalizing (PE) tympanostomy tubes may be
inserted to drain the fluid. This can prevent the
pressure build-up which can cause further ear
infections.
Tubes can restore normal hearing, prevent
persistent fluid build-up, reduce the frequency of
ear infections and prevent other serious ear
complications.
Sensorineural hearing loss
(treatable with modern technology)
Sensorineural hearing loss is caused by dysfunction
of the cochlea (sensory) or auditory pathways to
the brain (neural) and often is present from birth
(congenital). It can also develop as a result of noise
exposure, age or exposure to ototoxic medication.
Sensorineural hearing losses can range from mild
to profound and may affect all or only certain
frequency ranges. For example, high-pitched
sounds may not be detected while low-pitched
sounds are heard normally.
Sensorineural hearing loss is permanent and
cannot be treated with medicines or surgery. In
most cases people with this type of hearing loss
can be helped by hearing instruments or in some
cases by cochlear implants.
12
Hearing loss indicators
Infants – 29 days to 2 years
Concern regarding communication or
developmental delay
n Bacterial meningitis or other infections known
to cause sensorineural hearing loss
n Head trauma associated with loss of
consciousness or skull fracture
n Ototoxic medications including
chemotherapeutic agents or aminoglycosides
used in combination with loop diuretics
n Findings associated with a syndrome known to
include sensorineural hearing loss
n Otitis media with effusion (fluid) for three
months or longer
n
Outlined below are factors indicating that a child
is at risk for a hearing loss. If you are unsure about
any of these conditions or are worried about your
child’s hearing, consult a medical practitioner or
audiologist.
Newborns – birth to 28 days
n Failure of newborn hearing screening
n Family history of hereditary childhood
sensorineural hearing loss
n In utero infection, such as cytomegalovirus,
rubella, syphilis, herpes and toxoplasmosis
n Craniofacial deformities including those
affecting the pinna and ear canal
n Birth weight less than 1500 grams (approx. 3,5
pounds)
n Hyperbilirubinemia at a serum level requiring
transfusion (jaundice)
n Ototoxic medications (medicines that can
damage hearing), including aminoglycosides
(some antibiotics e.g. Gentamicin) used in
multiple courses or in combination with loop
diuretics
n Bacterial meningitis
n Apgar (general health) scores of 0–4 at 1
minute or 0–6 at 5 minutes after birth
n Mechanical ventilation lasting 5 days or longer
n Findings associated with syndromes known to
include sensorineural hearing loss
Noise exposure
One of the most common, and yet completely
preventable, causes of permanent sensorineural
hearing loss is noise exposure. High levels of noise
can cause temporary or permanent damage to the
sensory hair cells within the cochlea. Vehicles,
appliances and stereos, all produce noise which
may be detrimental to hearing, depending on how
loud the noise source is and the length of exposure.
In addition, some toys or computer games and
certainly rock music concerts can be loud enough
to damage hearing.
Children should be taught the dangers of noise
exposure and instructed to use ear protection
when necessary.
13
Mixed hearing loss
Sometimes a combination of factors occur which
affect both the outer or middle ear and the inner
ear (cochlea), resulting in a mixed hearing loss.
14
What to do if you think your child
may have a hearing loss
If you think a hearing loss may be present the first
step is to ask your medical practitioner to refer
your child for an audiological assessment. This
assessment will determine whether a hearing
impairment exists and to what degree. No child
is too young to receive a thorough hearing
evaluation. Today’s technology even allows
newborns to be tested for hearing loss.
While simple hearing screenings may be conducted
by nurses or trained volunteers, a complete
assessment of hearing in a child should only be
completed by an audiologist.
The purpose of the audiological evaluation is to
determine if a hearing loss exists, to what degree,
and to help discover what type. Test results are
recorded on an audiogram. If the results of the
tests show that your child has a hearing loss,
remember that your child is living in an age where
technology ensures that children with impaired
hearing can grow up to lead full and successful
lives.
15
Types of audiological evaluations
Behavioral hearing tests
These tests usually require the child to respond to
soft sounds in some way (verbally, by picture
pointing, raising the hand or through a game).
These tests can be fun and for infants and toddlers,
a head-turn response to a test signal is usually the
best and most reliable testing method.
Auditory brainstem response (ABR)
For newborns or infants and children who cannot
reliably perform the behavioral test procedures,
other more objective tests, such as ABR, can help
determine hearing abilities. Clicks or tonal “pips“
are sounded in an infant‘s ears through earphones.
The ABR provides information about the function
of the auditory pathway to the level of the
brainstem. The response to the clicks or tones are
recorded, providing an estimate of hearing
sensitivity.
Otoacoustic emissions (OAEs)
These tests provide a unique way to examine the
function of the cochlea. Sounds are sent to the
child‘s ear with a small loudspeaker. A microphone
records the response to the sound from the
cochlea (known as an emission). This offers
valuable information about the sensory hair cells
in the cochlea.
Tympanometry (acoustic immittance testing)
This test helps determine how well the eardrum
and middle ear are working. A gentle puff of air is
delivered into the child‘s ear and the amount the
eardrum moves in response to change in air
pressure is recorded. If the eardrum does not
move, for example, it could mean there is fluid
behind the eardrum and otitis media with effusion
may be present. If there is negative pressure it
could mean that the child is at-risk for devoloping
an ear infection.
16
Technological solutions
Today there is virtually no hearing loss that cannot
benefit from the use of appropriate technology.
After a clear diagnosis of hearing impairment
appropriate technology should be chosen as soon
as possible to ensure that your child can benefit
early from auditory experience. This technology
may take the form of a cochlear implant with an
electrode which is surgically implanted in the inner
ear and an external processor. This option is
increasingly utilized in cases of severe to profound
hearing loss. In many cases however, the most
appropriate choice may be hearing instruments.
These amplify sound and can help children of any
age.
The right choice of hearing instrument can help
your child develop good communication skills. A
young child is usually fit with behind-the-ear (BTE)
style hearing instruments. These hearing
instruments come in a variety of bright, cheerful
colors and can help a wide range of hearing
losses – mild, moderate and profound. Older
children may be candidates for the in-the-ear (ITE)
style hearing instruments which are custom-made
to fit inside the ear and help with mild-to-severe
hearing losses.
Another option for older children‘s are external
receiver style hearing instruments. The microphone
remains in the BTE casing but the receiver is
externally placed in the ear canal. This allows the
hearing instrument to be smaller and more
cosmetically appealing.
The decision whether the child should be fit with
one or two hearing instruments depends mainly
on the configuration of the hearing loss.
A wide range of hearing instrument accessories
are available to help children communicate better
over the phone, when listening to music and TV,
with Bluetooth devices or even just check the
status or adjust features.
17
18
Where to get help
While this booklet offers some general guidelines
for monitoring your child‘s hearing and
communication development, you may need
further information or have questions about how
to access resources regarding hearing in children.
In many countries federal and state laws exist that
mandate services for children who have hearing
impairments.
Hearing is not an all or nothing phenomenon. Even
a mild hearing loss during the crucial years for
language and speech development can cause a
child to misperceive speech sounds and may result
in a delay of normal communication development.
Your child‘s hearing is the means through which
spoken communication develops and flourishes.
Give hearing the attention it deserves and seek
professional help immediately if you are concerned.
For further information about children’s hearing
visit our website at: www.phonak.com
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